68 ANNUAL OF SCIENTIFIC DISCOVEKT. 



It appears from recent experiments conducted by the London 

 Pneumatic Conipnny, tluit ont; liundred and twenty tons of o;oods 

 can be sent through their eighteen miles of tubes every hour, at 

 a cost less than one penny a ton per mile. — Intellectual Observer 

 and Scientific American. 



AERIAL LOCOMOTION. 



A pamphlet has lately been published on this subject by Mr. 

 Bonllon, from which may be gatiu'rccl many interesting facts. 

 After giving it as his opinion that balloons will never jn'miit us, 

 safely and at pleasure, to navigate the air, on account of the A^ast 

 surface tliey present to the action of the wind, he proceeds to 

 show that if the prol)lem of aerial navigation is to be solved, the 

 encumbrance of balloons must be altogetiier dispensed with, and 

 an engine must be devised capable of lifting its own weight and 

 that of an aeronaut into the air, and of continuing to exert the 

 power requisite for this purpose for a consideral)l(! time. Tlierc 

 is no dillk-ulty in devising mechanical instruments lor aerial ])ro- 

 pulsion antl guidance. Earlier projectors j^i'iricipally aimed at 

 imitating (lie wings of bii'ds; but since the use of the screw for 

 the pr()j)ulsion of steamers, the employment of a similar propeller 

 for aerial locomotion naturally suggests itself. The action of such 

 a contrivance is illustrated by a small toy called the Stropheore,* 

 sold for the amusement of children ; Avhen a string pulled by the 

 hand, giving a rapid rotation to a miniature propeller, (muses it 

 to rise in the air. It is also illustrated by fire-works called the 

 Chinese turbine, which rise similarly in the air when caused 

 rapidh' to revolve by the combustion of the explosive mixture. 

 Tliere is no reason to apprehend any particular difllculty in the 

 mechanical adaptation of this principle to the purpose under con- 

 sideration. The real difficulty lies in obtaining a suitable motive 

 power, i. e., one capable of furnishing a sufficiency of power with- 

 out weight. In the case of the steam-engine, which first occurs 

 to the mind as the joossible agent of the propulsion, the chief ob- 

 jection is the Weight of the boiler, coals, and water ; that of the 

 cylinder, i)iston, and moving pai'ts being comparatively trifling. 

 The caloric-engine, although dispensing with the weight of water, 

 does not on the whole offer prospect of advantage. Another 

 source of motive power is offered by the combustion of gas, i. e., 

 by exploding a mixture of inflammable gas with atmospheric air. 

 In a gas-engine constructed on this principle, the weight of the 

 boiler, coals7 and water necessary to the steam-engine is alto- 

 gether dispensed with ; the place of these being supplied by a 

 receptacle of gas, a source not of weight but lightness. There is 

 one difficulty, however, viz., that if the receptacle of gas be 

 large, without which long journeys would be impossible, diffi- 

 culty of propulsion and guidance, as in the case of a balloon, 



* In the Stropheorg we have a few liglit ^\ings placed obliquely around a central 

 stem: h\ the action of the hands witli a string, as in a hummiiig-top, rotation is 

 imparted to those wings, and immediately the machine rises, and pierces its way 

 through tlie air. !>o long as t!ie motion continues, this ascent is continued, because 

 the ail-, subject to great compression, yields to impulsion before it has time to veer. 



